Improper Locking

In the Linux kernel, the following vulnerability has been resolved: drivers: staging: rtl8192e: Fix deadlock in rtllib_beacons_stop() There is a deadlock in rtllib_beacons_stop(), which is shown below: (Thread 1) | (Thread 2) | rtllib_send_beacon() rtllib_beacons_stop() | mod_timer() spin_lock_irqsave() //(1) | (wait a time) ... | rtllib_send_beacon_cb() del_timer_sync() | spin_lock_irqsave() //(2) (wait timer to stop) | ... We hold ieee->beacon_lock in position (1) of thread 1 and use del_timer_sync() to wait timer to stop, but timer handler also need ieee->beacon_lock in position (2) of thread 2. As a result, rtllib_beacons_stop() will block forever. This patch extracts del_timer_sync() from the protection of spin_lock_irqsave(), which could let timer handler to obtain the needed lock.Show less

In the Linux kernel, the following vulnerability has been resolved: drivers: usb: host: Fix deadlock in oxu_bus_suspend() There is a deadlock in oxu_bus_suspend(), which is shown below: (Thread 1) | (Thread 2) | timer_action() oxu_bus_suspend() | mod_timer() spin_lock_irq() //(1) | (wait a time) ... | oxu_watchdog() del_timer_sync() | spin_lock_irq() //(2) (wait timer to stop) | ... We hold oxu->lock in position (1) of thread 1, and use del_timer_sync() to wait timer to stop, but timer handler also need oxu->lock in position (2) of thread 2. As a result, oxu_bus_suspend() will block forever. This patch extracts del_timer_sync() from the protection of spin_lock_irq(), which could let timer handler to obtain the needed lock.Show less

In the Linux kernel, the following vulnerability has been resolved: drivers: staging: rtl8192bs: Fix deadlock in rtw_joinbss_event_prehandle() There is a deadlock in rtw_joinbss_event_prehandle(), which is shown below: (Thread 1) | (Thread 2) | _set_timer() rtw_joinbss_event_prehandle()| mod_timer() spin_lock_bh() //(1) | (wait a time) ... | _rtw_join_timeout_handler() del_timer_sync() | spin_lock_bh() //(2) (wait timer to stop) | ... We hold pmlmepriv->lock in position (1) of thread 1 and use del_timer_sync() to wait timer to stop, but timer handler also need pmlmepriv->lock in position (2) of thread 2. As a result, rtw_joinbss_event_prehandle() will block forever. This patch extracts del_timer_sync() from the protection of spin_lock_bh(), which could let timer handler to obtain the needed lock. What`s more, we change spin_lock_bh() to spin_lock_irq() in _rtw_join_timeout_handler() in order to prevent deadlock.Show less

In the Linux kernel, the following vulnerability has been resolved: drivers: staging: rtl8723bs: Fix deadlock in rtw_surveydone_event_callback() There is a deadlock in rtw_surveydone_event_callback(), which is shown below: (Thread 1) | (Thread 2) | _set_timer() rtw_surveydone_event_callback()| mod_timer() spin_lock_bh() //(1) | (wait a time) ... | rtw_scan_timeout_handler() del_timer_sync() | spin_lock_bh() //(2) (wait timer to stop) | ... We hold pmlmepriv->lock in position (1) of thread 1 and use del_timer_sync() to wait timer to stop, but timer handler also need pmlmepriv->lock in position (2) of thread 2. As a result, rtw_surveydone_event_callback() will block forever. This patch extracts del_timer_sync() from the protection of spin_lock_bh(), which could let timer handler to obtain the needed lock. What`s more, we change spin_lock_bh() in rtw_scan_timeout_handler() to spin_lock_irq(). Otherwise, spin_lock_bh() will also cause deadlock() in timer handler.Show less

In the Linux kernel, the following vulnerability has been resolved: drivers: staging: rtl8192u: Fix deadlock in ieee80211_beacons_stop() There is a deadlock in ieee80211_beacons_stop(), which is shown below: (Thread 1) | (Thread 2) | ieee80211_send_beacon() ieee80211_beacons_stop() | mod_timer() spin_lock_irqsave() //(1) | (wait a time) ... | ieee80211_send_beacon_cb() del_timer_sync() | spin_lock_irqsave() //(2) (wait timer to stop) | ... We hold ieee->beacon_lock in position (1) of thread 1 and use del_timer_sync() to wait timer to stop, but timer handler also need ieee->beacon_lock in position (2) of thread 2. As a result, ieee80211_beacons_stop() will block forever. This patch extracts del_timer_sync() from the protection of spin_lock_irqsave(), which could let timer handler to obtain the needed lock.Show less

In the Linux kernel, the following vulnerability has been resolved: drivers: tty: serial: Fix deadlock in sa1100_set_termios() There is a deadlock in sa1100_set_termios(), which is shown below: (Thread 1) | (Thread 2) | sa1100_enable_ms() sa1100_set_termios() | mod_timer() spin_lock_irqsave() //(1) | (wait a time) ... | sa1100_timeout() del_timer_sync() | spin_lock_irqsave() //(2) (wait timer to stop) | ... We hold sport->port.lock in position (1) of thread 1 and use del_timer_sync() to wait timer to stop, but timer handler also need sport->port.lock in position (2) of thread 2. As a result, sa1100_set_termios() will block forever. This patch moves del_timer_sync() before spin_lock_irqsave() in order to prevent the deadlock.Show less

In the Linux kernel, the following vulnerability has been resolved: drivers: staging: rtl8192eu: Fix deadlock in rtw_joinbss_event_prehandle There is a deadlock in rtw_joinbss_event_prehandle(), which is shown below: (Thread 1) | (Thread 2) | _set_timer() rtw_joinbss_event_prehandle()| mod_timer() spin_lock_bh() //(1) | (wait a time) ... | rtw_join_timeout_handler() | _rtw_join_timeout_handler() del_timer_sync() | spin_lock_bh() //(2) (wait timer to stop) | ... We hold pmlmepriv->lock in position (1) of thread 1 and use del_timer_sync() to wait timer to stop, but timer handler also need pmlmepriv->lock in position (2) of thread 2. As a result, rtw_joinbss_event_prehandle() will block forever. This patch extracts del_timer_sync() from the protection of spin_lock_bh(), which could let timer handler to obtain the needed lock. What`s more, we change spin_lock_bh() to spin_lock_irq() in _rtw_join_timeout_handler() in order to prevent deadlock.Show less

In the Linux kernel, the following vulnerability has been resolved: ceph: fix possible deadlock when holding Fwb to get inline_data 1, mount with wsync. 2, create a file with O_RDWR, and the request was sent to mds.0: ceph_atomic_open()--> ceph_mdsc_do_request(openc) finish_open(file, dentry, ceph_open)--> ceph_open()--> ceph_init_file()--> ceph_init_file_info()--> ceph_uninline_data()--> { ... if (inline_version == 1 || /* initial version, no data */ inline_version == CEPH_INLINE_NONE) goto out_unlock; ... } The inline_version will be 1, which is the initial version for the new create file. And here the ci->i_inline_version will keep with 1, it's buggy. 3, buffer write to the file immediately: ceph_write_iter()--> ceph_get_caps(file, need=Fw, want=Fb, ...); generic_perform_write()--> a_ops->write_begin()--> ceph_write_begin()--> netfs_write_begin()--> netfs_begin_read()--> netfs_rreq_submit_slice()--> netfs_read_from_server()--> rreq->netfs_ops->issue_read()--> ceph_netfs_issue_read()--> { ... if (ci->i_inline_version != CEPH_INLINE_NONE && ceph_netfs_issue_op_inline(subreq)) return; ... } ceph_put_cap_refs(ci, Fwb); The ceph_netfs_issue_op_inline() will send a getattr(Fsr) request to mds.1. 4, then the mds.1 will request the rd lock for CInode::filelock from the auth mds.0, the mds.0 will do the CInode::filelock state transation from excl --> sync, but it need to revoke the Fxwb caps back from the clients. While the kernel client has aleady held the Fwb caps and waiting for the getattr(Fsr). It's deadlock! URL: https://tracker.ceph.com/issues/55377Show less

In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: Fix potential AB/BA lock with buffer_mutex and mmap_lock syzbot caught a potential deadlock between the PCM runtime->buffer_mutex and the mm->mmap_lock. It was brought by the recent fix to cover the racy read/write and other ioctls, and in that commit, I overlooked a (hopefully only) corner case that may take the revert lock, namely, the OSS mmap. The OSS mmap operation exceptionally allows to re-configure the parameters inside the OSS mmap syscall, where mm->mmap_mutex is already held. Meanwhile, the copy_from/to_user calls at read/write operations also take the mm->mmap_lock internally, hence it may lead to a AB/BA deadlock. A similar problem was already seen in the past and we fixed it with a refcount (in commit b248371628aa). The former fix covered only the call paths with OSS read/write and OSS ioctls, while we need to cover the concurrent access via both ALSA and OSS APIs now. This patch addresses the problem above by replacing the buffer_mutex lock in the read/write operations with a refcount similar as we've used for OSS. The new field, runtime->buffer_accessing, keeps the number of concurrent read/write operations. Unlike the former buffer_mutex protection, this protects only around the copy_from/to_user() calls; the other codes are basically protected by the PCM stream lock. The refcount can be a negative, meaning blocked by the ioctls. If a negative value is seen, the read/write aborts with -EBUSY. In the ioctl side, OTOH, they check this refcount, too, and set to a negative value for blocking unless it's already being accessed.Show less

In the Linux kernel, the following vulnerability has been resolved: ath11k: Fix frames flush failure caused by deadlock We are seeing below warnings: kernel: [25393.301506] ath11k_pci 0000:01:00.0: failed to flush mgmt transmit queue 0 kernel: [25398.421509] ath11k_pci 0000:01:00.0: failed to flush mgmt transmit queue 0 kernel: [25398.421831] ath11k_pci 0000:01:00.0: dropping mgmt frame for vdev 0, is_started 0 this means ath11k fails to flush mgmt. frames because wmi_mgmt_tx_work has no chance to run in 5 seconds. By setting /proc/sys/kernel/hung_task_timeout_secs to 20 and increasing ATH11K_FLUSH_TIMEOUT to 50 we get below warnings: kernel: [ 120.763160] INFO: task wpa_supplicant:924 blocked for more than 20 seconds. kernel: [ 120.763169] Not tainted 5.10.90 #12 kernel: [ 120.763177] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kernel: [ 120.763186] task:wpa_supplicant state:D stack: 0 pid: 924 ppid: 1 flags:0x000043a0 kernel: [ 120.763201] Call Trace: kernel: [ 120.763214] __schedule+0x785/0x12fa kernel: [ 120.763224] ? lockdep_hardirqs_on_prepare+0xe2/0x1bb kernel: [ 120.763242] schedule+0x7e/0xa1 kernel: [ 120.763253] schedule_timeout+0x98/0xfe kernel: [ 120.763266] ? run_local_timers+0x4a/0x4a kernel: [ 120.763291] ath11k_mac_flush_tx_complete+0x197/0x2b1 [ath11k 13c3a9bf37790f4ac8103b3decf7ab4008ac314a] kernel: [ 120.763306] ? init_wait_entry+0x2e/0x2e kernel: [ 120.763343] __ieee80211_flush_queues+0x167/0x21f [mac80211 335da900954f1c5ea7f1613d92088ce83342042c] kernel: [ 120.763378] __ieee80211_recalc_idle+0x105/0x125 [mac80211 335da900954f1c5ea7f1613d92088ce83342042c] kernel: [ 120.763411] ieee80211_recalc_idle+0x14/0x27 [mac80211 335da900954f1c5ea7f1613d92088ce83342042c] kernel: [ 120.763441] ieee80211_free_chanctx+0x77/0xa2 [mac80211 335da900954f1c5ea7f1613d92088ce83342042c] kernel: [ 120.763473] __ieee80211_vif_release_channel+0x100/0x131 [mac80211 335da900954f1c5ea7f1613d92088ce83342042c] kernel: [ 120.763540] ieee80211_vif_release_channel+0x66/0x81 [mac80211 335da900954f1c5ea7f1613d92088ce83342042c] kernel: [ 120.763572] ieee80211_destroy_auth_data+0xa3/0xe6 [mac80211 335da900954f1c5ea7f1613d92088ce83342042c] kernel: [ 120.763612] ieee80211_mgd_deauth+0x178/0x29b [mac80211 335da900954f1c5ea7f1613d92088ce83342042c] kernel: [ 120.763654] cfg80211_mlme_deauth+0x1a8/0x22c [cfg80211 8945aa5bc2af5f6972336665d8ad6f9c191ad5be] kernel: [ 120.763697] nl80211_deauthenticate+0xfa/0x123 [cfg80211 8945aa5bc2af5f6972336665d8ad6f9c191ad5be] kernel: [ 120.763715] genl_rcv_msg+0x392/0x3c2 kernel: [ 120.763750] ? nl80211_associate+0x432/0x432 [cfg80211 8945aa5bc2af5f6972336665d8ad6f9c191ad5be] kernel: [ 120.763782] ? nl80211_associate+0x432/0x432 [cfg80211 8945aa5bc2af5f6972336665d8ad6f9c191ad5be] kernel: [ 120.763802] ? genl_rcv+0x36/0x36 kernel: [ 120.763814] netlink_rcv_skb+0x89/0xf7 kernel: [ 120.763829] genl_rcv+0x28/0x36 kernel: [ 120.763840] netlink_unicast+0x179/0x24b kernel: [ 120.763854] netlink_sendmsg+0x393/0x401 kernel: [ 120.763872] sock_sendmsg+0x72/0x76 kernel: [ 120.763886] ____sys_sendmsg+0x170/0x1e6 kernel: [ 120.763897] ? copy_msghdr_from_user+0x7a/0xa2 kernel: [ 120.763914] ___sys_sendmsg+0x95/0xd1 kernel: [ 120.763940] __sys_sendmsg+0x85/0xbf kernel: [ 120.763956] do_syscall_64+0x43/0x55 kernel: [ 120.763966] entry_SYSCALL_64_after_hwframe+0x44/0xa9 kernel: [ 120.763977] RIP: 0033:0x79089f3fcc83 kernel: [ 120.763986] RSP: 002b:00007ffe604f0508 EFLAGS: 00000246 ORIG_RAX: 000000000000002e kernel: [ 120.763997] RAX: ffffffffffffffda RBX: 000059b40e987690 RCX: 000079089f3fcc83 kernel: [ 120.764006] RDX: 0000000000000000 RSI: 00007ffe604f0558 RDI: 0000000000000009 kernel: [ 120.764014] RBP: 00007ffe604f0540 R08: 0000000000000004 R09: 0000000000400000 kernel: [ 120.764023] R10: 00007ffe604f0638 R11: 0000000000000246 R12: 000059b40ea04980 kernel: [ 120.764032] R13: 00007ffe604 ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: IB/rdmavt: add lock to call to rvt_error_qp to prevent a race condition The documentation of the function rvt_error_qp says both r_lock and s_lock need to be held when calling that function. It also asserts using lockdep that both of those locks are held. However, the commit I referenced in Fixes accidentally makes the call to rvt_error_qp in rvt_ruc_loopback no longer covered by r_lock. This results in the lockdep assertion failing and also possibly in a race condition.Show less

In the Linux kernel, the following vulnerability has been resolved: btrfs: zoned: traverse devices under chunk_mutex in btrfs_can_activate_zone btrfs_can_activate_zone() can be called with the device_list_mutex already held, which will lead to a deadlock: insert_dev_extents() // Takes device_list_mutex `-> insert_dev_extent() `-> btrfs_insert_empty_item() `-> btrfs_insert_empty_items() `-> btrfs_search_slot() `-> btrfs_cow_block() `-> __btrfs_cow_block() `-> btrfs_alloc_tree_block() `-> btrfs_reserve_extent() `-> find_free_extent() `-> find_free_extent_update_loop() `-> can_allocate_chunk() `-> btrfs_can_activate_zone() // Takes device_list_mutex again Instead of using the RCU on fs_devices->device_list we can use fs_devices->alloc_list, protected by the chunk_mutex to traverse the list of active devices. We are in the chunk allocation thread. The newer chunk allocation happens from the devices in the fs_device->alloc_list protected by the chunk_mutex. btrfs_create_chunk() lockdep_assert_held(&info->chunk_mutex); gather_device_info list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) Also, a device that reappears after the mount won't join the alloc_list yet and, it will be in the dev_list, which we don't want to consider in the context of the chunk alloc. [15.166572] WARNING: possible recursive locking detected [15.167117] 5.17.0-rc6-dennis #79 Not tainted [15.167487] -------------------------------------------- [15.167733] kworker/u8:3/146 is trying to acquire lock: [15.167733] ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: find_free_extent+0x15a/0x14f0 [btrfs] [15.167733] [15.167733] but task is already holding lock: [15.167733] ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_create_pending_block_groups+0x20a/0x560 [btrfs] [15.167733] [15.167733] other info that might help us debug this: [15.167733] Possible unsafe locking scenario: [15.167733] [15.171834] CPU0 [15.171834] ---- [15.171834] lock(&fs_devs->device_list_mutex); [15.171834] lock(&fs_devs->device_list_mutex); [15.171834] [15.171834] *** DEADLOCK *** [15.171834] [15.171834] May be due to missing lock nesting notation [15.171834] [15.171834] 5 locks held by kworker/u8:3/146: [15.171834] #0: ffff888100050938 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x1c3/0x5a0 [15.171834] #1: ffffc9000067be80 ((work_completion)(&fs_info->async_data_reclaim_work)){+.+.}-{0:0}, at: process_one_work+0x1c3/0x5a0 [15.176244] #2: ffff88810521e620 (sb_internal){.+.+}-{0:0}, at: flush_space+0x335/0x600 [btrfs] [15.176244] #3: ffff888102962ee0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_create_pending_block_groups+0x20a/0x560 [btrfs] [15.176244] #4: ffff8881152e4b78 (btrfs-dev-00){++++}-{3:3}, at: __btrfs_tree_lock+0x27/0x130 [btrfs] [15.179641] [15.179641] stack backtrace: [15.179641] CPU: 1 PID: 146 Comm: kworker/u8:3 Not tainted 5.17.0-rc6-dennis #79 [15.179641] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1.fc35 04/01/2014 [15.179641] Workqueue: events_unbound btrfs_async_reclaim_data_space [btrfs] [15.179641] Call Trace: [15.179641] <TASK> [15.179641] dump_stack_lvl+0x45/0x59 [15.179641] __lock_acquire.cold+0x217/0x2b2 [15.179641] lock_acquire+0xbf/0x2b0 [15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs] [15.183838] __mutex_lock+0x8e/0x970 [15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs] [15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs] [15.183838] ? lock_is_held_type+0xd7/0x130 [15.183838] ? find_free_extent+0x15a/0x14f0 [btrfs] [15.183838] find_free_extent+0x15a/0x14f0 [btrfs] [15.183838] ? _raw_spin_unlock+0x24/0x40 [15.183838] ? btrfs_get_alloc_profile+0x106/0x230 [btrfs] [15.187601] btrfs_reserve_extent+0x131/0x260 [btrfs] [15. ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: ubifs: Fix deadlock in concurrent rename whiteout and inode writeback Following hung tasks: [ 77.028764] task:kworker/u8:4 state:D stack: 0 pid: 132 [ 77.028820] Call Trace: [ 77.029027] schedule+0x8c/0x1b0 [ 77.029067] mutex_lock+0x50/0x60 [ 77.029074] ubifs_write_inode+0x68/0x1f0 [ubifs] [ 77.029117] __writeback_single_inode+0x43c/0x570 [ 77.029128] writeback_sb_inodes+0x259/0x740 [ 77.029148] wb_writeback+0x107/0x4d0 [ 77.029163] wb_workfn+0x162/0x7b0 [ 92.390442] task:aa state:D stack: 0 pid: 1506 [ 92.390448] Call Trace: [ 92.390458] schedule+0x8c/0x1b0 [ 92.390461] wb_wait_for_completion+0x82/0xd0 [ 92.390469] __writeback_inodes_sb_nr+0xb2/0x110 [ 92.390472] writeback_inodes_sb_nr+0x14/0x20 [ 92.390476] ubifs_budget_space+0x705/0xdd0 [ubifs] [ 92.390503] do_rename.cold+0x7f/0x187 [ubifs] [ 92.390549] ubifs_rename+0x8b/0x180 [ubifs] [ 92.390571] vfs_rename+0xdb2/0x1170 [ 92.390580] do_renameat2+0x554/0x770 , are caused by concurrent rename whiteout and inode writeback processes: rename_whiteout(Thread 1) wb_workfn(Thread2) ubifs_rename do_rename lock_4_inodes (Hold ui_mutex) ubifs_budget_space make_free_space shrink_liability __writeback_inodes_sb_nr bdi_split_work_to_wbs (Queue new wb work) wb_do_writeback(wb work) __writeback_single_inode ubifs_write_inode LOCK(ui_mutex) ↑ wb_wait_for_completion (Wait wb work) <-- deadlock! Reproducer (Detail program in [Link]): 1. SYS_renameat2("/mp/dir/file", "/mp/dir/whiteout", RENAME_WHITEOUT) 2. Consume out of space before kernel(mdelay) doing budget for whiteout Fix it by doing whiteout space budget before locking ubifs inodes. BTW, it also fixes wrong goto tag 'out_release' in whiteout budget error handling path(It should at least recover dir i_size and unlock 4 ubifs inodes).Show less

In the Linux kernel, the following vulnerability has been resolved: powerpc/set_memory: Avoid spinlock recursion in change_page_attr() Commit 1f9ad21c3b38 ("powerpc/mm: Implement set_memory() routines") included a spin_lock() to change_page_attr() in order to safely perform the three step operations. But then commit 9f7853d7609d ("powerpc/mm: Fix set_memory_*() against concurrent accesses") modify it to use pte_update() and do the operation safely against concurrent access. In the meantime, Maxime reported some spinlock recursion. [ 15.351649] BUG: spinlock recursion on CPU#0, kworker/0:2/217 [ 15.357540] lock: init_mm+0x3c/0x420, .magic: dead4ead, .owner: kworker/0:2/217, .owner_cpu: 0 [ 15.366563] CPU: 0 PID: 217 Comm: kworker/0:2 Not tainted 5.15.0+ #523 [ 15.373350] Workqueue: events do_free_init [ 15.377615] Call Trace: [ 15.380232] [e4105ac0] [800946a4] do_raw_spin_lock+0xf8/0x120 (unreliable) [ 15.387340] [e4105ae0] [8001f4ec] change_page_attr+0x40/0x1d4 [ 15.393413] [e4105b10] [801424e0] __apply_to_page_range+0x164/0x310 [ 15.400009] [e4105b60] [80169620] free_pcp_prepare+0x1e4/0x4a0 [ 15.406045] [e4105ba0] [8016c5a0] free_unref_page+0x40/0x2b8 [ 15.411979] [e4105be0] [8018724c] kasan_depopulate_vmalloc_pte+0x6c/0x94 [ 15.418989] [e4105c00] [801424e0] __apply_to_page_range+0x164/0x310 [ 15.425451] [e4105c50] [80187834] kasan_release_vmalloc+0xbc/0x134 [ 15.431898] [e4105c70] [8015f7a8] __purge_vmap_area_lazy+0x4e4/0xdd8 [ 15.438560] [e4105d30] [80160d10] _vm_unmap_aliases.part.0+0x17c/0x24c [ 15.445283] [e4105d60] [801642d0] __vunmap+0x2f0/0x5c8 [ 15.450684] [e4105db0] [800e32d0] do_free_init+0x68/0x94 [ 15.456181] [e4105dd0] [8005d094] process_one_work+0x4bc/0x7b8 [ 15.462283] [e4105e90] [8005d614] worker_thread+0x284/0x6e8 [ 15.468227] [e4105f00] [8006aaec] kthread+0x1f0/0x210 [ 15.473489] [e4105f40] [80017148] ret_from_kernel_thread+0x14/0x1c Remove the read / modify / write sequence to make the operation atomic and remove the spin_lock() in change_page_attr(). To do the operation atomically, we can't use pte modification helpers anymore. Because all platforms have different combination of bits, it is not easy to use those bits directly. But all have the _PAGE_KERNEL_{RO/ROX/RW/RWX} set of flags. All we need it to compare two sets to know which bits are set or cleared. For instance, by comparing _PAGE_KERNEL_ROX and _PAGE_KERNEL_RO you know which bit gets cleared and which bit get set when changing exec permission.Show less

In the Linux kernel, the following vulnerability has been resolved: gpio: xilinx: Convert gpio_lock to raw spinlock irq_chip functions may be called in raw spinlock context. Therefore, we must also use a raw spinlock for our own internal locking. This fixes the following lockdep splat: [ 5.349336] ============================= [ 5.353349] [ BUG: Invalid wait context ] [ 5.357361] 6.13.0-rc5+ #69 Tainted: G W [ 5.363031] ----------------------------- [ 5.367045] kworker/u17:1/44 is trying to lock: [ 5.371587] ffffff88018b02c0 (&chip->gpio_lock){....}-{3:3}, at: xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8)) [ 5.380079] other info that might help us debug this: [ 5.385138] context-{5:5} [ 5.387762] 5 locks held by kworker/u17:1/44: [ 5.392123] #0: ffffff8800014958 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3204) [ 5.402260] #1: ffffffc082fcbdd8 (deferred_probe_work){+.+.}-{0:0}, at: process_one_work (kernel/workqueue.c:3205) [ 5.411528] #2: ffffff880172c900 (&dev->mutex){....}-{4:4}, at: __device_attach (drivers/base/dd.c:1006) [ 5.419929] #3: ffffff88039c8268 (request_class#2){+.+.}-{4:4}, at: __setup_irq (kernel/irq/internals.h:156 kernel/irq/manage.c:1596) [ 5.428331] #4: ffffff88039c80c8 (lock_class#2){....}-{2:2}, at: __setup_irq (kernel/irq/manage.c:1614) [ 5.436472] stack backtrace: [ 5.439359] CPU: 2 UID: 0 PID: 44 Comm: kworker/u17:1 Tainted: G W 6.13.0-rc5+ #69 [ 5.448690] Tainted: [W]=WARN [ 5.451656] Hardware name: xlnx,zynqmp (DT) [ 5.455845] Workqueue: events_unbound deferred_probe_work_func [ 5.461699] Call trace: [ 5.464147] show_stack+0x18/0x24 C [ 5.467821] dump_stack_lvl (lib/dump_stack.c:123) [ 5.471501] dump_stack (lib/dump_stack.c:130) [ 5.474824] __lock_acquire (kernel/locking/lockdep.c:4828 kernel/locking/lockdep.c:4898 kernel/locking/lockdep.c:5176) [ 5.478758] lock_acquire (arch/arm64/include/asm/percpu.h:40 kernel/locking/lockdep.c:467 kernel/locking/lockdep.c:5851 kernel/locking/lockdep.c:5814) [ 5.482429] _raw_spin_lock_irqsave (include/linux/spinlock_api_smp.h:111 kernel/locking/spinlock.c:162) [ 5.486797] xgpio_irq_unmask (drivers/gpio/gpio-xilinx.c:433 (discriminator 8)) [ 5.490737] irq_enable (kernel/irq/internals.h:236 kernel/irq/chip.c:170 kernel/irq/chip.c:439 kernel/irq/chip.c:432 kernel/irq/chip.c:345) [ 5.494060] __irq_startup (kernel/irq/internals.h:241 kernel/irq/chip.c:180 kernel/irq/chip.c:250) [ 5.497645] irq_startup (kernel/irq/chip.c:270) [ 5.501143] __setup_irq (kernel/irq/manage.c:1807) [ 5.504728] request_threaded_irq (kernel/irq/manage.c:2208)Show less

In the Linux kernel, the following vulnerability has been resolved: irqchip/gic-v3-its: Don't enable interrupts in its_irq_set_vcpu_affinity() The following call-chain leads to enabling interrupts in a nested interrupt disabled section: irq_set_vcpu_affinity() irq_get_desc_lock() raw_spin_lock_irqsave() <--- Disable interrupts its_irq_set_vcpu_affinity() guard(raw_spinlock_irq) <--- Enables interrupts when leaving the guard() irq_put_desc_unlock() <--- Warns because interrupts are enabled This was broken in commit b97e8a2f7130, which replaced the original raw_spin_[un]lock() pair with guard(raw_spinlock_irq). Fix the issue by using guard(raw_spinlock). [ tglx: Massaged change log ]Show less

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: Fix inversion dependency warning while enabling IPsec tunnel Attempt to enable IPsec packet offload in tunnel mode in debug kernel generates the following kernel panic, which is happening due to two issues: 1. In SA add section, the should be _bh() variant when marking SA mode. 2. There is not needed flush_workqueue in SA delete routine. It is not needed as at this stage as it is removed from SADB and the running work will be canceled later in SA free. ===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected 6.12.0+ #4 Not tainted ----------------------------------------------------- charon/1337 [HC0[0]:SC0[4]:HE1:SE0] is trying to acquire: ffff88810f365020 (&xa->xa_lock#24){+.+.}-{3:3}, at: mlx5e_xfrm_del_state+0xca/0x1e0 [mlx5_core] and this task is already holding: ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30 which would create a new lock dependency: (&x->lock){+.-.}-{3:3} -> (&xa->xa_lock#24){+.+.}-{3:3} but this new dependency connects a SOFTIRQ-irq-safe lock: (&x->lock){+.-.}-{3:3} ... which became SOFTIRQ-irq-safe at: lock_acquire+0x1be/0x520 _raw_spin_lock_bh+0x34/0x40 xfrm_timer_handler+0x91/0xd70 __hrtimer_run_queues+0x1dd/0xa60 hrtimer_run_softirq+0x146/0x2e0 handle_softirqs+0x266/0x860 irq_exit_rcu+0x115/0x1a0 sysvec_apic_timer_interrupt+0x6e/0x90 asm_sysvec_apic_timer_interrupt+0x16/0x20 default_idle+0x13/0x20 default_idle_call+0x67/0xa0 do_idle+0x2da/0x320 cpu_startup_entry+0x50/0x60 start_secondary+0x213/0x2a0 common_startup_64+0x129/0x138 to a SOFTIRQ-irq-unsafe lock: (&xa->xa_lock#24){+.+.}-{3:3} ... which became SOFTIRQ-irq-unsafe at: ... lock_acquire+0x1be/0x520 _raw_spin_lock+0x2c/0x40 xa_set_mark+0x70/0x110 mlx5e_xfrm_add_state+0xe48/0x2290 [mlx5_core] xfrm_dev_state_add+0x3bb/0xd70 xfrm_add_sa+0x2451/0x4a90 xfrm_user_rcv_msg+0x493/0x880 netlink_rcv_skb+0x12e/0x380 xfrm_netlink_rcv+0x6d/0x90 netlink_unicast+0x42f/0x740 netlink_sendmsg+0x745/0xbe0 __sock_sendmsg+0xc5/0x190 __sys_sendto+0x1fe/0x2c0 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x4b/0x53 other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&xa->xa_lock#24); local_irq_disable(); lock(&x->lock); lock(&xa->xa_lock#24); <Interrupt> lock(&x->lock); *** DEADLOCK *** 2 locks held by charon/1337: #0: ffffffff87f8f858 (&net->xfrm.xfrm_cfg_mutex){+.+.}-{4:4}, at: xfrm_netlink_rcv+0x5e/0x90 #1: ffff88813e0f0d48 (&x->lock){+.-.}-{3:3}, at: xfrm_state_delete+0x16/0x30 the dependencies between SOFTIRQ-irq-safe lock and the holding lock: -> (&x->lock){+.-.}-{3:3} ops: 29 { HARDIRQ-ON-W at: lock_acquire+0x1be/0x520 _raw_spin_lock_bh+0x34/0x40 xfrm_alloc_spi+0xc0/0xe60 xfrm_alloc_userspi+0x5f6/0xbc0 xfrm_user_rcv_msg+0x493/0x880 netlink_rcv_skb+0x12e/0x380 xfrm_netlink_rcv+0x6d/0x90 netlink_unicast+0x42f/0x740 netlink_sendmsg+0x745/0xbe0 __sock_sendmsg+0xc5/0x190 __sys_sendto+0x1fe/0x2c0 __x64_sys_sendto+0xdc/0x1b0 do_syscall_64+0x6d/0x140 entry_SYSCALL_64_after_hwframe+0x4b/0x53 IN-SOFTIRQ-W at: lock_acquire+0x1be/0x520 _raw_spin_lock_bh+0x34/0x40 xfrm_timer_handler+0x91/0xd70 __hrtimer_run_queues+0x1dd/0xa60 ---truncated---Show less

In the Linux kernel, the following vulnerability has been resolved: afs: Fix merge preference rule failure condition syzbot reported a lock held when returning to userspace[1]. This is because if argc is less than 0 and the function returns directly, the held inode lock is not released. Fix this by store the error in ret and jump to done to clean up instead of returning directly. [dh: Modified Lizhi Xu's original patch to make it honour the error code from afs_split_string()] [1] WARNING: lock held when returning to user space! 6.13.0-rc3-syzkaller-00209-g499551201b5f #0 Not tainted ------------------------------------------------ syz-executor133/5823 is leaving the kernel with locks still held! 1 lock held by syz-executor133/5823: #0: ffff888071cffc00 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline] #0: ffff888071cffc00 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: afs_proc_addr_prefs_write+0x2bb/0x14e0 fs/afs/addr_prefs.c:388Show less

In the Linux kernel, the following vulnerability has been resolved: virtio-blk: don't keep queue frozen during system suspend Commit 4ce6e2db00de ("virtio-blk: Ensure no requests in virtqueues before deleting vqs.") replaces queue quiesce with queue freeze in virtio-blk's PM callbacks. And the motivation is to drain inflight IOs before suspending. block layer's queue freeze looks very handy, but it is also easy to cause deadlock, such as, any attempt to call into bio_queue_enter() may run into deadlock if the queue is frozen in current context. There are all kinds of ->suspend() called in suspend context, so keeping queue frozen in the whole suspend context isn't one good idea. And Marek reported lockdep warning[1] caused by virtio-blk's freeze queue in virtblk_freeze(). [1] https://lore.kernel.org/linux-block/ca16370e-d646-4eee-b9cc-87277c89c43c@samsung.com/ Given the motivation is to drain in-flight IOs, it can be done by calling freeze & unfreeze, meantime restore to previous behavior by keeping queue quiesced during suspend.Show less